Toothbrushes have traditionally utilized one or more groups of bristles that are fixed or otherwise attached to the head or end of the toothbrush. Toothbrushes are also known that utilize movable bristle sets or holders that are mechanically or electrically powered. Typically, an electric motor and a drive mechanism are retained within the body of the toothbrush and are coupled to the movable bristle sets or holders. Upon actuation of the motor and drive mechanism, the bristle holders may undergo a variety of different types of motion. Typically, one or more batteries are also provided within the body of the toothbrush to power the drive mechanism and impart motion to the movable bristle holders.
During operation of an electric toothbrush, power consumption of the electric motor is generally a function of the rate of rotation and load placed upon the motor by the drive mechanism. These parameters are dependent upon the load placed upon the brushing elements, e.g. the moving bristle holders, disposed on the brush head. It is also known that power consumption of the electric motor is also dependent upon the mechanical strain placed upon the motor, and typically, upon the output shaft of the motor.
A significant disadvantage in using an electric toothbrush is that after some time period of repeated use, the batteries are exhausted and must be replaced. In addition to the increasingly high cost of batteries, battery replacement is often regarded by consumers as burdensome or annoying. In addition, in certain low cost disposable electric toothbrushes, the batteries may be sealed within the body of the toothbrush and not be suitable for replacement. Accordingly, a need exists for extending battery life and the time period between battery replacement in an electric toothbrush.
Additionally, a need remains for an improved technique and assembly for increasing battery life in an electric toothbrush, particularly for instances besides those involving excessive strain or bending of a brush head or neck.